/*
 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 *
 */
package com.luqili.utils.pub.link;

import java.io.Serializable;
import java.util.Objects;

/**
 * <p>
 * A convenience class to represent name-value pairs.
 * </p>
 *
 * @since JavaFX 2.0
 */
public class Pair<K, V> implements Serializable {
    /**
     *
     */
    private static final long serialVersionUID = -716684370480123543L;
    /**
     * Key of this <code>Pair</code>.
     */
    private K key;
    /**
     * Value of this this <code>Pair</code>.
     */
    private V value;

    /**
     * Creates a new pair
     *
     * @param key   The key for this pair
     * @param value The value to use for this pair
     */
    public Pair(K key, V value) {
        this.key = key;
        this.value = value;
    }

    /**
     * Gets the key for this pair.
     *
     * @return key for this pair
     */
    public K getKey() {
        return key;
    }

    /**
     * Gets the value for this pair.
     *
     * @return value for this pair
     */
    public V getValue() {
        return value;
    }

    /**
     * <p>
     * <code>String</code> representation of this <code>Pair</code>.
     * </p>
     *
     * <p>
     * The default name/value delimiter '=' is always used.
     * </p>
     *
     * @return <code>String</code> representation of this <code>Pair</code>
     */
    @Override
    public String toString() {
        return key + "=" + value;
    }

    /**
     * <p>
     * Generate a hash code for this <code>Pair</code>.
     * </p>
     *
     * <p>
     * The hash code is calculated using both the name and the value of the <code>Pair</code>.
     * </p>
     *
     * @return hash code for this <code>Pair</code>
     */
    @Override
    public int hashCode() {
        // name's hashCode is multiplied by an arbitrary prime number (13)
        // in order to make sure there is a difference in the hashCode between
        // these two parameters:
        // name: a value: aa
        // name: aa value: a
        return key.hashCode() * 13 + (value == null ? 0 : value.hashCode());
    }

    /**
     * <p>
     * Test this <code>Pair</code> for equality with another <code>Object</code>.
     * </p>
     *
     * <p>
     * If the <code>Object</code> to be tested is not a <code>Pair</code> or is <code>null</code>, then this method returns <code>false</code>.
     * </p>
     *
     * <p>
     * Two <code>Pair</code>s are considered equal if and only if both the names and values are equal.
     * </p>
     *
     * @param o the <code>Object</code> to test for equality with this <code>Pair</code>
     * @return <code>true</code> if the given <code>Object</code> is equal to this <code>Pair</code> else <code>false</code>
     */
    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }

        if (o instanceof Pair) {
            @SuppressWarnings("rawtypes")
            Pair pair = (Pair) o;
            if (!Objects.equals(key, pair.key)) {
                return false;
            }
            if (!Objects.equals(value, pair.value)) {
                return false;
            }
            return true;
        }
        return false;
    }
}
